ECS is a fairly "late" idea in game development history, "just stuff widgets in arrays" works just fine in small games. But when you have - commercial games ge

ECS is a fairly "late" idea in game development history, "just stuff widgets in arrays" works just fine in small games. But when you have - commercial games getting too big for any one single person to keep track of all those widgets getting developed in parallel - engines being developed as standalone generic projects to be used in many, many games that need solid abstractions - enough RAM to justify the overhead (whole megabytes! Scandalous!) ...then ECS starts making a lot of sense. That was in the late 90s/early 00s, and these days the (performance) overhead is negligible even for indie game dev. The only potential downside is the cognitive overhead, but that very much depends on what you're doing.